4,481 research outputs found
sj-docx-1-jiv-10.1177_08862605221118967 – Supplemental material for Prevalence and Predictors of Poly-Victimization of Adolescents in England and Wales
No full textSupplemental material, sj-docx-1-jiv-10.1177_08862605221118967 for Prevalence and Predictors of Poly-Victimization of Adolescents in England and Wales by Ferhat Tura, Eleftherios Nomikos and Lucy R. Betts in Journal of Interpersonal Violence</p
Data from paper - 'Proxies for basement structure and its implications for Mesoproterozoic metallogenic provinces in the Gawler Craton' on Journal of Geophysical Research - Solid Earth. 2018/2019.
No full textThis file contains data related to the publication 'Proxies for basement structure and its implications for Mesoproterozoic metallogenic provinces in the Gawler Craton' on Journal of Geophysical Research - Solid Earth. 2018/2019.Authorship by J.G. Motta, P. G. Betts, C.R. Souza Filho, S. Thiel, S. Curtis, R. J. Armit Data made available by the corresponding author J. G. Motta ([email protected]).Please see text document within the compressed file for clarification.</div
High density endocardial mapping of shifts in the site of earliest depolarization during sinus rhythm and sinus tachycardia
No full textPrevious mapping studies of sinus rhythm suggest faster rates arise from more cranial sites within the lateral right atrium. In the intact, beating heart, mapping has been limited to epicardial plaques or single endocardial catheters. The present study was designed to examine shifts in the site of the earliest endocardial depolarization during sinus rhythm and sinus tachycardia using high density activation mapping. Noncontact mapping of the right atrium during sinus rhythm was performed on ten anesthetized swine. Recordings were made during sinus rhythm, phenylephrine infusion, and isoproterenol infusion. The hearts were then excised and the histological sinus node identified. The mean minimum and maximum cycle lengths recorded were355 ± 43and717 ± 108 ms. A median of three (range two to five) sites of earliest endocardial depolarization were documented in each animal. With increasing heart rate the site of earliest endocardial depolarization remained stationary until a sudden shift in a cranial or caudal direction, often to sites beyond the histological sinoatrial node. The endocardial shift was unpredictable with considerable variation between animals; however, faster rates arose from more cranial sites(r = 0.46, P = 0.023). There was no difference in the mean cycle length of sinus rhythm originating from specific positions on the terminal crest(r = 0.44, P = 0.17). Cranial sites displayed a more diffuse pattern of early depolarization than caudal sites. In the porcine heart the relationship between heart rate and site of earliest endocardial depolarization shows considerable variation between individual animals. These findings may have implications for clinical mapping and ablation procedures
Data from paper - 'Proxies for basement structure and its implications for Mesoproterozoic metallogenic provinces in the Gawler Craton' on Journal of Geophysical Research - Solid Earth. 2018/2019.
No full textThis file contains data related to the publication 'Proxies for basement structure and its implications for Mesoproterozoic metallogenic provinces in the Gawler Craton' on Journal of Geophysical Research - Solid Earth. 2018/2019.<div><br></div><div>Authorship by J.G. Motta, P. G. Betts, C.R. Souza Filho, S. Thiel, S. Curtis, R. J. Armit <br><div><br></div><div>Data made available by the corresponding author J. G. Motta ([email protected]).</div><div><br></div><div>Please see text document within the compressed file for clarification.</div></div>
Global dynamic coupling of activation and repolarization in the human ventricle
No full textBackground: The ability to determine spatial and dynamic changes in ventricular repolarization may help to understand arrhythmogenic mechanisms in humans. We hypothesized that noncontact mapping could be used to investigate global activation-repolarization coupling in the human ventricle during steady state and premature extrastimulation.Methods and Results: Activation-recovery intervals (ARIs) determined from reconstructed unipolar electrograms by the Ensite system were analyzed during sinus rhythm, constant pacing, spontaneous ventricular ectopic beats, and premature stimulation at intermediate and short coupling intervals in the left or right ventricle of 13 patients (6 female; mean age, 48 years) without structural myocardial disease. ARIs were measured from 32 sites in each ventricle with the use of a method validated with monophasic action potential recordings and unipolar contact electrograms. Global T-wave distribution was displayed on a 3-dimensional geometry of the ventricle, with polarities opposite to the direction of activation during steady state and premature stimulation. There was a significant inverse correlation between activation times and ARIs during sinus rhythm, ventricular ectopy, and premature stimulation (r=0.72, slope=–0.76, P<0.001). Premature stimuli at short coupling intervals flattened the regression slope compared with sinus rhythm (–0.61 versus –0.81; P=0.05), but the global pattern of repolarization was preserved. In comparison to our method, the Wyatt method of ARI measurement failed to demonstrate significant coupling between activation and repolarization (r=0.34, slope=0.19).Conclusions: Global, dynamic repolarization mapping of the human ventricle is feasible. An inverse coupling of activation and repolarization during steady state and premature stimulation may preserve electric stability in the normal ventricle
Determination of human ventricular repolarization by noncontact mapping: validation with monophasic action potential recordings
No full textBackground: Noncontact mapping (NCM) has not been validated as a clinical technique to measure ventricular repolarization. We used NCM to determine repolarization characteristics by analysis of reconstructed unipolar electrograms (UEs) at the same sites as monophasic action potential (MAP) recordings in the human ventricle.Methods and Results: MAPs were recorded from a total of 355 beats at 46 sites in the left or right ventricle of 9 patients undergoing ablation of ventricular tachycardia guided by NCM (EnSite system). Measurements were made during sinus rhythm, constant right ventricular pacing, and ventricular extrastimuli during restitution-curve construction. The EnGuide locator signal was used to document MAP catheter locations on the endocardial geometry. UE-determined activation-recovery interval (ARI) measured at the maximum derivative of the T wave (Wyatt method) and the minimum derivative of the positive T wave (alternative method) was correlated with MAP measured at 90% repolarization (MAP90%) at the same sites. ARI correlated with MAP90% during steady state by the Wyatt method (r=0.83, P<0.001) and the alternative method (r=0.94, P<0.001). Restitution curves constructed from MAP and UE data exhibited the same characteristics, with a mean correlation coefficient of 0.95 (range, 0.90 to 0.99, P<0.001). The error between ARI and MAP90% was greater over a shorter diastolic coupling interval but was not influenced by distance of the sampling site from the multielectrode array.Conclusions: NCM accurately determines steady-state and dynamic endocardial repolarization in humans. Global, high-density, NCM data could be used to characterize abnormalities of human ventricular repolarization
R. T. P. Allen: The Texas Years, 1857-1865
No full textIn 1857, R. T. P. Allen moved from near Frankfort, Kentucky, to Bastrop, Texas, to found the Bastrop Military Institute. In 1861 he enlisted in the Confederate army and in 1862 was named colonel of the 17th Texas Infantry. He was wounded at the battle of Milliken\u27s Bend and was then assigned to Camp Ford near Tyler, Texas, which was evolving into a prisoner of war camp. He remained there until replaced in May, 1864, when he resigned due to ill health and returned to his Bastrop school. At the end of the war, with all military schools prohibited in previously Confederate states, he moved back to Frankfort and Kentucky Military Institute
The two-legged stool: the neglected role of educational standards in improving America's public schools
No full textThe author notes that raising the school-leaving age and increasing the amount of spending per pupil have been extremely important public school reforms. However, he says, sizable improvements in school quality will only be evident when these two reforms are complemented by higher standards--and when students' abilities to meet these standards are tested.Education
Environmental Impact Assessment, on the Operation of Conventional and More Electric Large Commercial Aircraft
No full textGlobal aviation is growing exponentially and there is a great emphasis on trajectory optimization to reduce the overall environmental impact caused by aircraft. Many optimization techniques exist and are being studied for this purpose. The CLEAN SKY Joint Technology Initiative for aeronautics and Air transport, a European research activity run under the Seventh Framework program, is a collaborative initiative involving industry, research organizations and academia to introduce novel technologies to improve the environmental impact of aviation. As part of the overall research activities, "green" aircraft trajectories are addressed in the Systems for Green Operations (SGO) Integrated Technology Demonstrator. This paper studies the impact of large commercial aircraft trajectories optimized for different objectives applied to the on board systems. It establishes integrated systems models for both conventional and more electric secondary power systems and studies the impact of fuel, noise, time and emissions optimized trajectories on each configuration. It shows the significant change in the fuel burn due to systems operation and builds up the case as to why a detailed aircraft systems model is required within the optimization loop. Typically, the objective in trajectory optimization is to improve the mission performance of an aircraft or reduce the environmental impact. Hence parameters such as time, fuel burn, emissions and noise are key optimization objectives. In most instances, trajectory optimization is achieved by using models that represent such parameters. For example aircraft dynamics models to describe the flight performance, engine models to calculate the fuel burn, emissions and noise impact, etc. Such techniques have proved to achieve the necessary level of accuracy in trajectory optimization. This research enhances previous techniques by adding in the effect of systems power in the optimization process. A comparison is also made between conventional power systems and more electric architectures. In the conventional architecture, the environmental control system and the ice protection system are powered by engine bleed air while actuators and electrics are powered by engine shaft power off-takes. In the more electric architecture, bleed off take is eliminated and the environmental control system and ice protection system are also powered electrically through engine shaft power off takes
Should start up companies be cautious? Inventory policies which maximise survival probabilities
No full textNew start-up companies, which are considered to be a vital ingredient in a successful economy, have a different objective than established companies: They want to maximise their chance of long-term survival. We examine the implications for their operating decisions of this different criterion by considering an abstraction of the inventory problem faced by a start-up manufacturing company. The problem is modelled under two criteria as a Markov decision process; the characteristics of the optimal policies under the two criteria are compared. It is shown that although the start-up company should be more conservative in its component purchasing strategy than if it were a well-established company, it should not be too conservative. Nor is its strategy monotone in the amount of capital it has available. The models are extended to allow for interest on investment and inflation
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